How to Make It
Spray a 12-cup mini muffin tin with cooking spray (or line with mini muffin liners).
Place chopped chocolate and coconut oil in a heatproof bowl set over a saucepan of simmering water; stir occasionally until melted, 2 to 3 minutes. Pour chocolate into the bottom of 12 mini muffin cups until the chocolate just covers the bottom of the cups, reserving some for the top layer. Place in the freezer for 5 minutes.
Divide the peanut butter evenly among the cups. Top with more chocolate until the peanut butter is just covered and freeze until solid, about 30 minutes. To pop them out of the muffin tin, run a knife around the edge of each cup.